Gate emit unit tests on JitDumpEmitUnitTests instead of define

[a74nh]

• Add a common genEmitterUnitTests()
• Add a config option JitDumpEmitUnitTests instead of using #defines.
• Add basic string checking to decide which groups to run
• Add a code to jump over the tests to prevent coreclr from running the tests (which usually causes a segfault loading from bad memory)

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Issue Details

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Author:	a74nh
Assignees:	-
Labels:	area-CodeGen-coreclr, community-contribution
Milestone:	-

[a74nh]

@kunalspathak @BruceForstall - as suggested on #95918

[BruceForstall]

This looks great, except it looks like some "garbage" code to be removed.

As a follow-up, I think we should move all the arm64 unit tests to a separate file (named codegenarm64test.cpp?) since they're now over 5000 lines in this 11000 line file.

[a74nh]

As a follow-up, I think we should move all the arm64 unit tests to a separate file (named codegenarm64test.cpp?) since they're now over 5000 lines in this 11000 line file.

Done.

[kunalspathak]

seems like we don't need the altjit check, because we should be able to generate the new sve when running natively on arm64?

runtime/src/coreclr/jit/codegenxarch.cpp

Lines 9048 to 9052 in 6d0a902

	if (!compiler->opts.altJit)
	{
	// No point doing this in a "real" JIT.
	return;
	}

[kunalspathak]

LGTM. Thanks for doing it.

[kunalspathak]

nit: will be good to mention example usage like should they be comma-separated, etc. May be in a follow-up PR.

[a74nh]

seems like we don't need the altjit check, because we should be able to generate the new sve when running natively on arm64?

runtime/src/coreclr/jit/codegenxarch.cpp

Lines 9048 to 9052 in 6d0a902

	if (!compiler->opts.altJit)
	{
	// No point doing this in a "real" JIT.
	return;
	}

I originally had this check in the new common function. But then Arm64 testing would always exit without doing the tests. So, I removed it for all targets because it's gated by the config option anyway.